Double lesion MRgFUS treatment of essential tremor targeting the thalamus and posterior sub-thalamic area: preliminary study with two year follow-up

Background MR-guided focused ultrasound (MRgFUS) is an effective treatment for essential tremor (ET). However, the optimal intracranial target sites remain to be determined. Objective To assess MRgFUS induced sequential lesions in (anterior-VIM/VOP nuclei) the thalamus and then posterior subthalamic area (PSA) performed during the same procedure for alleviating ET. Methods 14 patients had unilateral MRgFUS lesions placed in anterior-VIM/VOP then PSA. Bain-Findley Spirals were collected during MRgFUS from the treated arm (BFS-TA) and throughout the study from the treated (BFS-TA) and non-treated (BFS-NTA) arms and scored by blinded assessors. Although, the primary outcome was change in the BFS-TA from baseline to 12 months we have highlighted the 24-month data. Secondary outcomes included the Clinical Rating Scale for Tremor (CRST), Quality of Life for ET (QUEST) and PHQ-9 depression scores. Results The mean improvement in the BFS-TA from baseline to 24 months was 41.1% (p